I definitely agree in the case of the Conjuring films and its spinoffs. To me, the best, most lasting horror is always built off of a central metaphor, which the "horror" elements serve to give a face to, to externalize and exaggerate. The Shining has the specter of alcoholism and domestic abuse, The Descent is about grief and betrayal, Triangle is an absolute masters thesis on guilt and self-punishment. The Conjuring flicks don't really have any central metaphor (the core of their message seems to be, "There are scary things in the world, and you should always hire professionals to deal with them"), but they're still highly enjoyable, worthwhile horror films, simply on the strength of the aesthetics and the actual filmmaking craft involved. Even if you don't necessarily have anything to say, you can still make a good horror movie if the WAY you say it is strong enough.